code: def test_save_all(self, tmp_path):
      temp_file = str(tmp_path / "temp.webp")
      im = Image.new("RGB", (1, 1))
      im2 = Image.new("RGB", (1, 1), "#f00")
      im.save(temp_file, save_all=True, append_images=[im2])
  
      with Image.open(temp_file) as reloaded:
          assert_image_equal(im, reloaded)
  
          reloaded.seek(1)
          assert_image_similar(im2, reloaded, 1)
  
imports: from __future__ import annotations
  import io
  import re
  import sys
  import warnings
  import pytest
  from PIL import Image, WebPImagePlugin, features
  from .helper import assert_image_equal, assert_image_similar, assert_image_similar_tofile, hopper, skip_unless_feature
label_desc: Use image node_id 7 for calling the TestFileWebp obj's underlying member method code with example usage: obj.test_save_all(tmp_path) without return types